Technical Field
This disclosure relates to devices and methods for performing a capsulotomy, and more specifically, devices and methods for using an electrical cutting element to cut a membrane of the eye during a capsulotomy.
Description of the Related Art
Lens cataract is the leading cause of blindness worldwide and surgical treatment by cataract removal is the treatment of choice. If the lens of an eye develops opaque areas, as in a cataract, the lens must be surgically removed. The lens can be replaced with an artificial intraocular lens (IOL) to provide better vision after cataract removal. There may also be other reasons such as presbyopia to replace a lens that is not serving its functions appropriately.
The removal of the lens for replacement with an IOL is a surgical procedure that requires substantial precision. The lens is completely enclosed by a membrane called the lens capsule, so the surgeon must first cut through the capsule to access the lens. Creating an opening in the lens capsule with the required level of precision is a difficult task for a surgeon controlling and guiding conventional handheld cutting instruments and attempting to trace a precise circular route on the lens capsule. Currently, to perform a capsulotomy (the creation of an opening in the lens capsule), the surgeon typically manually creates a small tear in the anterior region of the lens capsule, and uses a small forceps to try to extend the edge of the tear so as to follow a circular path of the specified diameter and centered on the optic axis of the eye. In practice, it often happens that the hole does not end up circular, or the correct diameter, or centered on the optic axis. There can also be radial tears in the edge of the hole that greatly weaken the capsule. As a result of any of these errors, the capsule may not be able to hold the IOL properly, and optimal visual outcome cannot be achieved.
Microsurgery instruments commonly are not sufficiently compact or streamlined in shape, making it difficult for a surgeon to minimize the incision size or possibly risking tears or other damage at the incision site. Cutting elements or other sharp components are sometimes exposed during insertion, requiring the surgeon to be very precise and creating further risk of collateral damage to tissue when inserting the instrument through the incision. Further, this insertion often requires multiple steps and sometimes complex maneuvering of instruments by the surgeon, leaving little room for error. Once inserted, instruments are often not easily manipulated and the surgeon may be forced to handle and move multiple separate pieces in a small space. Any of these problems can make it very difficult for a surgeon to access a second layer of tissue behind a first layer, particularly when the second layer is tissue in a very small area, such as within the eye.
Given the drawbacks of existing treatment devices/procedures for accessing tissue, such as the lens capsule, to perform surgery, improved techniques and devices for performing microsurgery and capsulotomy are needed.